Delivery device and method for its operation

ABSTRACT

A system of marked medical containers comprises at least two containers having different properties in at least one respect, and at least one machine-readable marking on each of the containers, each marking being designed to allow discrimination between the difference in properties. Each marking allows discrimination between the difference by having at least one area with different absorbence or reflectance when irradiated with radiation in non-visible frequency ranges. A specific container comprises a syringe cartridge type container for use with a preparation delivery device.

TECHNICAL FIELD

The present invention relates to a preparation delivery devicecomprising a) a container for the preparation having or being preparedfor the arrangement of an opening, b) a mechanism operable to deliver atleast part of the preparation in the container through the opening, c)attachment means for connection of the container to the mechanism and d)a sensor system arranged to detect at least one predetermined propertyof the container or its content. The invention also relates to anoperation method for such a device, to containers or container systemfor use in the device and a marking system or analyzing device relatingto components of the device.

BACKGROUND OF THE INVENTION

Injection devices based on a separate delivery mechanism attachable toreplaceable containers have found widespread use in many areas, such asmedical delivery systems, owing to the flexibility and economy containedin the possibility of providing a reusable pump type device with more orless advanced machinery for preparing, dosing, controlling andmonitoring the injection procedure whereas the replaceable containerfeatures can be limited to those necessary for safe confinement andsimple expulsion of the pharmaceutical, features which furthermore maybe adapted to each individual preparation type.

Delivery devices are known for use in more permanent set-ups, e.g. forhospital treatment situations, where there are few design restrictionsand the pump part can be highly sophisticated in view of motorizedmanipulation means, processor controlled operation and data collectionas well as possible interfacing against other available instrumentation.Often the design freedom is also utilized to make the pump partcompatible with one or several existing or standardized cartridge,syringe or injection device types, hereby increasing the applicationrange for the instrument and reducing adaptation costs for the cartridgepart.

For ambulatory purposes the design limitations are more severe,especially for self-contained devices without connectable support. Sizeand weight restrictions place limitations on the number andsophistication degree of functions possible to include. Automation as analternative measure for increasing safety and avoiding misuse issimilarly restricted by the added motorized means and operationrepertoire by limited capacity of energy storage means. Although handyand portable injectors may be devised with the minimum of supportfeatures necessary to safely control all the abovesaid requirements andproblems in the hands of a skilled operator, a general trend inlong-term medication is to place the administration responsibility onthe patient himself, also in the case of child or disabled persons, e.g.by use of pen-type injectors. A high degree of automation and control isthen desirable to avoid mistakes, not only at the mere injections stepsbut also the critical initiation and preparation steps. Patientsdependent on daily administrations also have a legitimate need forconvenience and devices discrete enough to be brought around in dailylife. The contradictory requirements on highly sophisticated and yetsmall and convenient devices need to be met by new technology.

Delivery devices both for permanent and ambulatory use need a reliablesensor system for container control and verification in broad sense. Themere range of container types attachable to the general purpose pumpsfor stationary use in itself creates a control problem and for portabledevices the option of patient self-administration require a fail-safecontrol and the widespread distribution of pumps and containerscorresponding precautions against intended or unintended misuse orabuse. The reliance on automation for most functions in the devicesassumes an input to the processor of for example the presence ofcontainer, check of its condition, verification of its non-used statusand information of container type, content, concentration, expire dateetc. It may also be desirable to input individual patient data andadministration schemes. Even when the pump device is intended only for asingle or a few container types or contents the pump should beinoperable but with these containers, also when intentional efforts aremade to circumvent the safety systems. It is clear that the desirablecontrols may be of quite varying nature. Pure information may betransferred from a machine readable marking on the container to thedevice, which information may be totally unrelated to the container asin the case of patient data or a security code or related thereto as inthe case of markings representing container preparation type and volume.Control of physical container characteristics, such as size andorientation, and functional properties, such as presence of preparationand plunger position, may require a non-standard design of the containerwith special features for sensing, a highly sophisticated all purposemonitoring system or multiple specialized sensors for each feature to bedetected, all of which alternatives are incompatible with the abovesaidgeneral demands placed on stationary or portable pump systems.

Common information carrying marking techniques are not suitable for thepurposes outlined. The patent specifications U.S. Pat. No. 4,978,335 andWO 93/02720 suggest among other the use of a bar code and a bar codereader for similar purposes. Bar codes do not carry much information ona given surface, require a reader of significant size which can notconveniently be housed in small devices, utilizes a complex radiationsystems and the code as such is easily manipulated and hence not safeagainst forgery. Finally the system is not usable for sensing any othercontainer characteristic than the specified coding. Similardisadvantages and restrictions are present with marking systems based onreading of alphanumeric characters, magnetic strips etc.

Sensors for physical or functional container properties seem to bescarce in the prior art. Systems based on switches, as represented byU.S. Pat. No. 4,838,857, activated by a container when in properposition, give a highly inflexible sensing system unless a multitude ofswitches are arranged and a system susceptible to wear andcontamination. Also systems based on interlocking of mating structures,as exemplified by EP 549 694, are inflexible, unprecise and easilycheated and, to the extent special key features are provided on thecartridge part, not compatible with standard containers. Knownprinciples seem to be highly specialized, easily manipulated and notadaptable for a complementary information reading.

Accordingly there remains a need for a sensing system able to meet thevarious demands in especially medical delivery devices while beingcompatible with the typical restraints in these applications. Althoughthe present invention has a more general utility, it will mainly bedescribed against this background.

SUMMARY OF THE INVENTION

A main object of the present invention is to offer a sensor systemlimiting the abovesaid disadvantages with prior art suggestions. A morespecific object is to offer such a system useful in medical deliverydevices. Another object is to provide such a system suitable for use inportable devices by having small size, low weight and low energyconsumption. A further object is to provide a reliable and not easilymanipulated system. Still another object is to provide a system able tosense marked information in a reliable way. Another object is to providea system able to sense a variety of functional properties. Yet anotherobject is to devise a system able to sense both marked information andfunctional properties. A further object is to offer a sensor systembeing highly compatible with automation and microcontroller processingof its output.

These objects are reached with a system having the characteristics setforth in the appended claims.

By using in the system of the invention the general principle oftransmitting radiation towards the object to be sensed and receiving forfurther analysis radiation affected by the object, several of theabovesaid objects are reached. Mechanical contact between sensor andobject need not be present thereby increasing positioning and useflexibility while reducing problems with wear and contamination.Flexibility is also provided by the variety of mutualtransmitter/receiver positioning possibilities available. By detectingfunctional object properties on the basis of a comparison betweenradiation received and a predetermined representation thereof, thesystem becomes highly flexible and adaptable to many object propertiesand the same receiver may be used for detection of several properties.The criteria for defining the predetermined representation may beunknown to the user and accordingly difficult to satisfy by unauthorizedindividuals. Use of non-imaging or even de-focused radiation has severaladvantages. Very simple and cheap components can be utilized. A largetake up area in both width and depth facilitates positioning of thecomponents and allows radiation received from different depths to affectthe response with equal significance, of value for example withtransparent objects such as in common medical containers. In sensing offunctional properties this flexibility, as well as the possibility tolet every interface surface affect the response, give a broad range ofpotentially detectable properties which may be covered by a single or afew receivers and also permit monitoring of dynamically changingproperties. In sensing of marked information a large take up area may beemployed to reduce misreading due to contamination, increase informationamount by using multiple analog response levels in addition tostructures in the marking and strongly improve security by using markingfeatures not readily detectable by visual inspection. The latter pointmay be further improved on by using radiation in non-visible frequencyranges. It is clear that the same system can be used for sensing bothfunctional properties and marked information, typically needed inmedical delivery applications, and being highly beneficial where size,weight, economy and energy consumption matters, as in portable articles.Adaptation to automation is simple owing to the few componentsnecessary, the simple driving thereof, the compatibility with scanningactions or dynamic operations and the easy processing also in real timeof a sequential output from the receiver.

Further objects and advantages will become evident from the detaileddescription of the invention hereinbelow.

DETAILED DESCRIPTION General

As used herein “system” shall be understood to refer to the inventiongenerally, when including its parts, such as devices, methods ofoperation, marking principles and crucial component such as pump partsand containers.

As indicated in the introduction the sensor system and markingprinciples thereof described herein may be used for a variety ofpurposes within and beyond the medical area and for any type ofpreparations, such as chemicals, compositions or mixtures, in anycontainer and delivered for any purpose. For reasons outlined the systemhas certain special values in connection with medical delivery deviceswhere also the design constraints are more severe than in most otherapplications. For convenience the invention will be described in termsof this application.

The principles of the present invention may be used for delivery devicesor systems in broad terms The delivery means from the device may be aninfusion channel or any conducting means such as a tube or catheter, aneedle or cannula or a needle-less system based on liquid jet or aparticle gun with gas propellant. The container content material shallbe deliverable by use of a delivery mechanism and any materialfulfilling this requirement can be used. Normally the material is afluid and preferably a liquid, including materials behaving as liquidssuch as emulsions or suspensions. These observations relates to thefinal preparation whereas other components, notably solids, may bepresent before final preparation. The nature of container content shallalso be understood to include medical in broad terms and to embrace forexample natural components and body fluids prefilled or drawn into thecontainer although most commonly the medical is factory prepared. Theinvention may assist in solving special problems in connection withsensitive compounds susceptible to degradation or denaturation undermechanical stress such as high shear forces. Compounds of high molecularweight may be of this type, high molecular weight hormones for examplegrowth hormones or prostaglandins. The invention may also assist insolving special problems in connection with medicals requiring apreparation step immediately prior to the infusion, typically a mixingof two or more components, which all may be fluid or may include a solidas when dissolving a lyophilized powder in a solvent, such as hormonesor prostaglandins.

The administration manner can also be varied within broad limits and mayinclude entirely continuous infusion, continuous infusion with varyingflow or intermittent infusions or injections with repeated either equalor varying doses. Especially when combined with automation means in apreferred way the administration manner can easily be varied byadaptations in software or similar control. In portable devices theintermittent administration is common. Similarly, although deliverydevices may be contemplated also for a single dosing operation,generally they are designed for more than one or multiple individualdoses for intermittent administration.

In addition to the basic functions for delivery purposes the deliverysystem with preference may include other valuable features such as forinitiating the container and its content and provide various checks andcontrols of both the container and the pump part electronics andmechanics.

As mentioned in the introduction the principles of the invention may beapplied to delivery devices in stationary or permanent set-ups. Due toamong others the simplicity provided the invention give specialadvantages in delivery devices for ambulatory purposes, especially thosebeing autonomous with on-board energy storage, motor and processor meansand in particular small hand-held devices of truly portable nature.

A preferred medication delivery device can be said to generally compriseat least a container for the medication having or being prepared for thearrangement of an opening, a mechanism operable to deliver at least partof the medication in the container through the opening, attachment meansfor connection of the container to the mechanism and a sensor systemarranged to detect at least one predetermined property of the containeror its content.

The Container

The container part shall be understood in broad sense and may take avariety of forms such as any kind of tube, vessel, flexible bag, vial,ampoule, cartridge, carpoule, syringe body etc. There are someadvantages in using containers that are rigid, at least at its openingor the part for attachment to the mechanism but preferably generallyrigid, such as vials, ampoules or syringe bodies. There are also someadvantages in employing the invention in connection with containers thatare at least translucent and preferably transparent at least partiallyand preferably generally at the frequency of the radiation used. Commoncontainer materials such as glass or plastic can with preference beused. The container may an integral or composite structure, such asincluding an outer casing or any other multipart construction forclosures, fixtures, protection etc., and whenever used herein“container” shall be understood to include any auxiliary part present.

The container has at least one opening through which the medication passduring the main delivery operation of the device, either from thecontainer interior to the surrounding for e.g. administration of themedical to the patient or to the container in case of aspiration of bodyfluids or at preparation steps such as filling, mixing or dissolution inthe container, during which operations the opening need to be present.It is possible and even in many situations preferred that certain deviceoperations, such as label reading, container control or initiation,takes place before communication has been established and the openingrequirement shall then be considered satisfied by the preparation meansfor creating the communication such as the presence of a removableclosure or a pierceable or rupturable part on the container itself as inthe case of an ampoule or bag or a specially designed part as in case ofpenetrable membranes or septurn. All communication may take placethrough one opening, for example both medical passage and pressureequalization in a rigid container or by delivery from a container whichis flexible or has a movable or deformable part but nothing preventsthat further openings are provided for similar purposes, which can beidentical to the at least one opening but which can be entirelydifferent and for example be adapted for another purpose of e.g.infusion or syringe type with a movable wall or piston.

The container may be a simple bottle, vial or bag in case the deliverydevice is arranged to withdraw, continuously or intermittently, meteredamounts therefrom for delivery as defined. Often, and especially inconnection with self-administration, the container type is moreelaborate and is commonly in the form of a cartridge, being thecontainer part of a syringe type of delivery system, which may be stillmore elaborate in the case of multichamber cartridges. Cartridge typecontainers shall be further described as they generally requireadditional initiation or control steps for which the principles of theinvention with preference can be exploited.

A cartridge for the present purposes may generally be said to include avessel having a front part and a rear part defining a general cartridgeaxis, an outlet for the preparation arranged at the front part and atleast one movable wall arranged at the rear part, a displacement ofwhich wall causes the preparation to be moved towards or expelledthrough the outlet. Vessel shape and movable wall have to be mutuallyadapted. The vessel may be designed most freely when the wall is aflexible or oversized membrane or diaphragm able to adapt by movement orreshaping to vessel internal surfaces, in which case a fluid cushion orresilient material may be needed between the wall and piston rod tosmooth out applied pressure. Preferably, however, the vessel has asubstantially constant internal cross-section, with a similarly constantvessel axis, between front and rear parts giving a generally tube-shapedvessel, and most preferably the cross-section is of the common circulartype giving a substantially cylindrical vessel. The movable wall is thenpreferably a substantially shape-permanent, although possibly elastic,body sealingly adapted to the internal vessel surface and preferably ofthe plunger type having sufficient length to self-stabilize againsttumbling during travel along the vessel. The front part outlet may be ofany known design and directed laterally for best access in certainapplications, frontal but non-coaxial with vessel axis or most commonlyarranged frontal and coaxial. The outlet may be integral with the vesselor in a conventional manner the cartridge front end may be provided withan attachment therefore and before connection be provided with abreakable or penetrable sealing.

Generally the described cartridges need several kinds of initiationactions, dependent on a displacement of the movable wall, to reset thedevice and make possible repeated and reproducible dosing meeting highprecision demands. In its first movement the movable wall may need anextraordinary break-loose force after storage to overcome both internalreshaping resistance and an increased wall friction due to adherence ordepletion of lubricant in contact points. Also in relation to the weakerregular injection force, elastic and inelastic deformations andtolerances have to be evened out in the movable wall, cartridge shell,outlet attachments et cetera The preparations themselves may havecompressible inclusions such as gas vesicles. Deaeration and preelectionis needed to remove gas in the vessel compartment and fill out spacesfor example at the front sealings, outlet attachments and the interiorof the outlet devices or needles.

Dual or multi chamber cartridge types are known e.g. for preparationsdemanding a mixing of two or more components or precursors beforeadministration. The components are kept separated by one or moreintermediate walls of different known designs, which walls divide thevessel into several chambers, sometimes placed parallel along cartridgeaxis but most commonly in stacked relationship along the axis.Unification of the components may take place by breaking, penetrating oropening a valve construction in the intermediate walls, for example byintroducing a pin or needle through the cartridge front, through or atthe rear movable wall or by means at the cartridge exterior (comparee.g. the cited WO 93/02720). In another known design the intermediatewall or walls are of the plunger type and flow communication between thechambers is accomplished by moving the plunger to a by-pass sectionwhere the interior wall has one or several enlarged sections or repeatedcircumferential grooves and lands in a manner allowing by-flow of rearchamber content into front chamber at displacement of the rear movablewall (compare e.g. U.S. Pat. No. 4,968,299 or WO 93/20868 and WO95/11051). The chambers may contain gas, liquid or solids. Generally atleast one liquid is present. Most commonly in pharmaceuticalapplications only two chambers are present and typically contains oneliquid and one solid, the latter being dissolved and reconstitutedduring the mixing operation.

Initiation of the multi-chamber type cartridges requires all the generaltype steps described, although in aggravated form due to the additionalwalls and spaces present. In order to provide for efficient mixinggenerally a mixing space has to be allotted in addition to the spaceoccupied by the component volumes. Powdered components in bulk form alsorequire the extra space contained in interstices between particles. Themixing step may produce foam or gas inclusions requiring space to settleout. Plunger type intermediate walls generally have to be displaced atleast their own length to reach the non-sealing site in the by-pass. Intotal multi-chamber type cartridges require long movable wall strokes inthe initiating step, both for mixing and subsequent deaeration, andbenefit in a particular way from the advantages of the currentinvention.

Cartridge sizes may vary strongly depending on the intended applicationand general ranges are difficult to give. Typical sizes in the preferredself-administration application by use of portable devices are 2 to 30mm internal diameter and preferably 3 to 20 mm.

The Mechanism

The mechanism for delivery of medical through the container openingshould basically include at least one type of pumping means which mayhave to be selected for the special kind or container and medical used.The pumping means may include any kind of pressure source, such asmechanical or electrolytic pressure build-up, in the container andsuitable valve means for control, which method can be used withvirtually any kind of container and any kind of product, such astransdermal delivery of powder, as exemplified by WO 94/24263, similardelivery through liquid jets, as exemplified by WO 94/2188, or regulartube infusion, as exemplified by WO 88/09187. Any kind of container canalso be used with pumps based on peristaltic action or centrifugalaction, although also for general use pumps based on controlled positivedisplacement are preferred and especially such pumps based on a separatecylinder and piston action, as exemplified by U.S. Pat. No. 5,480,381for liquid jet or U.S. Pat. No. 4,564,360 for a manually operated needlebased device. The common syringe type container need a specializedpumping system. Either the mechanism is adapted to act on completesyringes, having their own piston rods, by engaging and axiallydisplacing said rod, as exemplified by the initially referenced U.S.Pat. No. 4,978,335, which may be preferred when it is desired toaccommodate syringes of many different types and sizes, or the mechanismhas a piston rod acting more or less directly on the piston of acartridge type container, as exemplified by WO 95/26211, EP 143.895 orEP 293.958, which can be made smaller and more adapted to portabledevices. Also dual or multiple chamber cartridges can use a similardevices for its various phases, as exemplified by the initiallymentioned WO 93/02720. Although the various pump mechanisms discussedmay include mechanical means for affecting the medical or a piston themeans, such as a piston rod, may be actuated by any known means, such asgas pressure, vacuum, hydraulics, springs or manual operation. It ispreferred to actuate the pump means by electric means such as anelectrical motor, indirectly or preferably directly, among othersbecause of its ease of adaptation to an overall automated device.

The mechanism may preferably include further components. The mechanismmay for example include special means for securing doses delivered, e.g.by direct metering of medical delivered, although it is generallypreferred to utilize directly or indirectly the pump means for this,e.g. by monitoring axial displacement or the rotation of a piston rodaxis in a manner known per se. In particular it is preferred that themechanism includes a control system operative to perform at least partof the abovementioned administrative patterns, initiation of containersor cartridges, self-control or surveillance and possible recording ofoperation steps conducted. Such systems are known in the art, asexemplified by U.S. Pat. No. 4,529,401, and may be designed in amultitude of ways. For the purposes of the present invention it ispreferred that the control system drives and monitors at least part ofthe sensor system and processes data obtained therefrom.

The Attachment Means

The minimum requirement on the attachment means is to connect thecontainer to the mechanism in such a manner as to allow the mechanism toperform its pumping function. The nature of pump and container principleselected may determine how critical is the relative positioning betweencontainer and mechanism. Generally when the mechanism is based on aseparate pump or control valve principle with a conduit to the containerthe relative positioning is not critical. When the container itself is apart of the pumping or dosing principle, as for syringe or cartridgetype containers, when the mechanism directly act on the container therelative positioning may be highly critical with direct influence ondosing precision. In the non-critical situations it is conceivable tohave the container freely or flexibly connected to the mechanism, e.g.via a tube, although preferred, at least in portable devices, to rigidlyaffix the container to the mechanism as well as in case of the abovesaidcritical situations. If the mechanism is generally divided in astationary parts, for example including actuating means, chassis andtransmissions, and functional movable parts, for example the active partin a pump, such as a piston rod, or in a delivery controlling valvemechanism, it is preferred to affix the container relative thestationary parts, directly or indirectly, although possible to move thecontainer towards the mechanism during delivery. A convenient way ofimplementing the indirect relative attachment between stationary partsand container is to provide a housing in which at least the stationarymechanism parts are enclosed in relative immobility and to which housingthe container is attached. When present the housing shall be regarded asthe point of reference for motions unless otherwise stated.

The abovediscussed relative positioning is valid for the phase when themechanism delivers medication through the container opening. Under otherphases the attachment means may cooperate with the mechanism to provideother functions. A preferred such function it to cause a movement of thecontainer. Preferably the container moves at least in relation to thestationary parts of the mechanism and preferably also in relation to thehousing when present. Such a movement may be used e.g. in a dockingmaneuver for the cartridge including for example an attraction and alocking of the container. Alternatively or in combination the containermay move in relation to the movable parts of the mechanism. Such amovement can with preference be used to perform an action on thecontainer, especially for the purpose of initiating a container orcartridge as has been described. A preferred method and device for thelatter purpose is disclosed in our copending application of even dateentitled “Injection device and method for its operation” included byreference herein. A further object of any of the abovesaid motions is tomove the container relative the sensor system, although this can also bemade by moving the sensor system relative the mechanism or the housing.Relative movement between sensors and the container will hereinafter bereferred to as “scanning”. Scanning may be used for various sensingpurposes, to be further discussed below, such as sensor reading ofinformation or use of the same sensor for different purposes, spatiallyor sequentially. In the present context shall be observed that withpreference any movement for scanning purposes can be combined withmovements for any of the abovesaid purposes in order to facilitate theoverall device and operation, such as a parallel initiation of acartridge and reading and checking thereof. Movement for any purposementioned may include both axial and rotational displacements, asunderstood in terms of a container of generally rotational symmetry suchas a vial or cartridge. As an example, initiation or attraction mayrequire an axial movement whereas a rotational movement can be used forlocking. For scanning purposes an axial movement may serve both readingand control of functional properties along the container whereas arotational movement may serve to read more information distributed overcontainer mantle surface or to shift scanning purpose.

Scanning speeds can be selected freely. The sensor system is generallycompatible with most speeds, even stationary readings, and speeds canwith preference be adapted to the other purposes mentioned. Typicallythe movement take place with less than 100 cm/sec. preferably less than10 cm/sec and most preferably less than 1 cm/sec. Suitably the speedsare above 0.1 and also over 0.5 mm/sec.

When a housing is present it may be desirable to extend the housing atleast partially and preferably substantially all over the container, forexample for the purpose of protecting the container, provide guidingfeatures to stabilize it staticly or dynamically during movement thereofor in particular to arrange sensor means in case unless positioned oncarriers, stationary or movable, of their own, which housing enclosuremay also act to reduce stray radiation from the surroundings. Certainlythe housing can be designed as a composite or unitary structure.

The nature of the physical means for actual attachment of the containerto the mechanism or housing is generally not critical for the presentobjects and can be of any conventional or known type, such as based onfriction, push lock, undercut, bayonet lock, threads or any other fit.

The Sensor System

The sensor system of the invention is based on the transmission andreception of radiation. In the preferred application the radiation isdirected towards the container or any marking thereof although, asindicated, the principles may have a more general utility as ananalytical systems for objects generally or a system for machinereadable information generally. In terms of the preferred applicationthe description of the sensor system will be divided in the radiationtechnique, the sensor applications and the signal processing.

Radiation Technique

Initially shall be noted that although the transmitter and receiver havebeen discussed in the present context as if discrete components, orintegral components containing both at a mutual gap distance, theterminology shall be understood to include “transceivers” i.e.components performing both functions, simultaneously or interchangeably,either with the same active component performing both functions orpreferably, for best adaptation, with separate components housed withinthe same enclosure. Transmitters, receivers and transceivers willhereinafter collectively be referred to as “active elements”. Allcomponents shall be understood in broad sense and for example anycomponent made to output a response to beam alterations shall beregarded as a receiver and any source for radiation, natural butpreferably artificial, used by the receiver shall be regarded atransmitter.

Any kind of radiation which can be affected in a detectable way by thecontainer or a marking can be used in the sensor system. Preferably theradiation is electromagnetic radiation with a suitable frequency rangebetween ultraviolet and microwaves and most preferably in the opticaland infrared regions. As earlier indicated there are security advantagesin using radiation in the non-visible ranges. The transmitter may be amaser or laser, lamps or most preferably light emitting diodes (LED's)which are preferably used for the visible and most preferably theinfrared frequency range, such as between 300 to 3000 nanometers orbetween 500 to 2000 nanometers. Good results have been obtained in thevisible area as well as infrareds in 950, 870 and 875 nanometers. Thereceiver should be adapted to the transmitter and for the above giventypes the receiver may be a photoresistor or better a photodiode orphototransistor. The receiver should be adapted in frequency to thetransmitter or in case of fluorescence to any frequency resultingtherefrom. For both transmitter and receiver frequency adaptation can bemade by selection of type, by use of optical filters or application ofelectronic filters. For devices not operating in the visible range issuitable to incorporate a daylight filter to remove inadvertentsurrounding influence. The specific selection of components will bedependent on which imaging principle shall be used.

As used herein an “imaging” system shall be understood as a system ableto reproduce an object with details in at least two dimensions, normallyrequiring a system able to provide a resolution of pixels, points orlines, in the object in the two dimensions, which may take lace indifferent ways. A “focusing” imaging method may be used in which a lenstype system give a true two-dimensional reproduction of the object,which reproduction, for example imaged on a cathode ray tube orradiation sensitive semiconductor such as a Charge Coupled Device, e.g.to give a pixel map or a line by line two dimensional output for lateranalysis. The focusing method may efficiently use available radiationand be focused to different depth of interest. Alternatively a“sweeping” imaging method can be used in which the object is swept pointby point, which may give more general depth information and a sequentialoutput. The sweeping can take place by irradiating the object with broadangle illumination while reception is restricted to a narrow sweepingspot by shielding or lens focusing. A more preferred method is toilluminate the object by a narrow sweeping spot, either a thin parallelbeam from e.g. a laser type of transmitter or a shielded or lens focusedspot from a divergent radiation source, and receive radiation from theobject by a receiver which can have a narrow take-up angle butpreferably has wide angle reception area. In order to give the imagingresult an arrangement for providing sweeping of at least the narrow spotpart should be present, e.g. by moving the active element itself, itsshielding or focusing part as mentioned or a separate deflecting partssuch as a mirror, lens or prism.

A “non-imaging” or integrating system shall be understood as a systemdesigned to respond with a unified or single signal to the totalradiation received from an area of the object. A non-imaging principlehas the advantage of a strong simplification of the sensor system, bothin respect of hardware and afterprocessing. Still with the methodsaccording to the invention the non-imaging system give adequate controlresults and is preferred for most of the present purposes. A non-imagingsystem need not have a sweeping arrangement for reconstruction of atwo-dimensional image but it is preferred that the active elements,after any modification as described, give a transmission and receptionrespectively, which has a stable axis orientation in relation to thesupport for the active element. In static sensing of container positionsaid support is fixed in relation to the container. In scanning betweensensor and container as described said axis orientation may still bestable but the support and container movable in relation to each other,preferably with the sensor fixed and the container movable in relationto a housing as described. All in all a fixed arrangement of the axisorientation and the active element support in relation to the mechanismor a housing is preferred for simplest overall design.

Although a focused image can be allowed to fall on the receiver also inthe non-imaging method it has little meaning as a unified response isdelivered. It is generally preferred to allow “de-focused” radiation tofall on the receiver and then preferably at least the radiation from theforemost part of the object, closest to the receiver, and mostpreferably radiation received substantially from all depths, should bede-focused. This may require that the radiation directed towards thereceiver is out-of-focus convergent, parallel or preferably divergent.It is preferred that also the transmitter gives off de-focused radiationin the sense that an area covering irradiation is used, such as a widebeam of parallel radiation, an out-of-focus convergent radiation orpreferably a divergent radiation. With preference the area or anglecovered by the transmitter can be larger than the area or angle coveredby the receiver. In addition to a valuable simplification of the sensorsystem possible, the de-focused radiation method has the advantage ofgiving a response from a substantial space in both width and depth ofthe object. This principle allows the system to register a composite“fingerprint” response of the object part observed, which is not onlyhighly unique but also highly difficult to mimic, more so if registeredin the non-visible frequency range. These advantages are amplified ifthe area covered by the receptor is fairly large in relation to theobject and if the area covered is not sharply, but softly or gradually,delimited from non-covered areas. As the object type and target partthereof may vary strongly, absolute area values are difficult to give. Asuitable space angle, with any means for correction present, drawn withits vertex at receptor axis base and with its wide end covering thetake-up area, can be for example be above 10, preferably above 30 andmost preferably above 45 degrees. The angle may be very large but isgenerally less than 180 degrees, preferably less than 160 and mostpreferably less than 140 degrees. The take-up area is commonly andpreferably circular but when not, these values relates to a circulararea of the same size as the actual.

Selection of hardware depends on which of the above sensor systemprinciples is chosen. As indicated a sweeping spot can be obtained by ashielded divergent source, better by a lens system or a laser typedevice. A parallel beam can be obtained by a collimator lens system or alaser type device. A divergent beam can be obtained with a plain diffusetransmitter for simplicity or a lens system for best control. Similarlythe receiver reception angle can be adjusted by shielding but better bya lens system for control and energy efficiency.

Between transmission and reception the radiation shall be affected bythe object, which can take place in a multitude of ways. Generally thephenomena at play are reflection, transmission, absorption andscattering. For example, radiation meeting a change in refractive indexfor the radiation frequency used will be reflected to a higher or lowerextent. The reflection may be diffuse if irregularities are present ormay otherwise preserve a wave front and give an imaging mirror type ofreflection. Radiation not reflected may be transmitted through thesurface and possibly refracted. Passage may then cause absorption,roughly exponential energy fall off with transmission length, whichabsorption like the reflection may be diffuse when irregularities arepresent or otherwise imaging. Scattering may be caused by diffusereflection and transmission.

The degree to which these phenomena affects the radiation may bestrongly frequency dependent, which can be used to amplify desirabledifferences. In principle this can be done at two extremes. Either anarrow bandwidth or even a monochrome radiation is selected at thefrequency maximizing the effect desired. A narrow bandwidth can beobtained by filtering out, through absorption or refraction, a singlefrequency from a basically broadband radiation source, by use of a lasertype of transmitter, by use of emission spectra bands or any othermethod. One advantage of narrow bandwidths is high signal to noiseratios and less influence from random background radiation. Anotheradvantage is that either the transmitter or receiver component can beselected of simple broadband type since the output is still determinedby the single common frequency. A specific advantage is that aspectroscopic analysis of for example a container content is possible,which may require measurement of more than one single frequency ortuning single frequencies over a range, such as establishing an IRspectra over the component. A further advantage is the possibility todetect a frequency change intentionally introduced for marking purposessuch as a fluorescence. At the other extreme a broadband radiation canbe used, preferably by selecting broadband components for bothtransmitter and receiver. Broadband components, such as lamps, lightemitting diodes and photodiodes or phototransistors, are readilyavailable, are cheap and are energy economic. Broadband radiationfurther allow more object characteristics to affect the radiation. Forexample an analysis corresponding to color analysis in the visibleregion can be conducted. In most applications a broadband approach ispreferred. A suitable width is then at least a variation coefficient of1 percent, preferably at least 5 percent and most preferably at least 10percent, plus and minus the nominal frequency, defined at the frequencywhere the level has fallen to less than 30 percent of the maximum level.

The radiation may be affected by the abovedescribed phenomena at severalparts of the objects. Besides an area covered by the transmitter andreceptor, the influence may take place at different depth of the object,such as the two surfaces of the front container surface, the content ofthe container and the two surfaces of the wall of the other side of thecontainer, possibly repeated in any casing surfaces, as well as at anycrack or other irregularity in these parts. Alternatively the radiationmay be blocked at a first surface by a barrier to the radiation such asmetal for optical and infrared radiation. Similarly the radiation may beaffected repeated reflection or repeated scattering, e.g. from thecontainer or a surrounding housing, such as a cavity filling diffuseradiation. It is also possible to introduce active measures for creatingdetectable differences. For example, the housing part may be given acharacteristic distinctive to the cartridge part to allow detection ofcontainer presence or a particular functional part of a container orcartridge may be marked for detection. For example, one part may bedesigned to reflect radiation and another part to absorb radiation. Asan example, for visible or infrared electromagnetic radiation carbonblack can be used for absorbency and metal or titanium oxide asreflective materials.

A further degree of freedom is the relative positioning of the activeelements, both in relation to each other and the active elements inrelation to the object. For the sake of description, the transmittershall be described with reference to its main beam axis, being thecentral axis, symmetry axis or axis of maximum intensity as the case maybe, after the beam has been given a directionality by shielding, a lenssystem etc. when present. Similarly the main receptor axis of thereceptor shall be its central, symmetry or maximum intensity uptake axisafter possible correction by shielding, lens systems etc. An axis planeshall be understood as a plane in which the axis lies. Assuming firstthat both the transmitter axis and the receptor axis lie in the sameplane, they can form a variety of angles with each other. Both can pointin substantially the same direction with substantially parallel axes,i.e. with about zero degrees angle between the axes as with atransceiver type of active element. This arrangement is advantageouswhen concentrating on reflected radiation from the object but can alsobe used for transmitted light if there is some reflection within orbehind the object, e.g. by in installed mirror type surface. The activeelements can be placed opposely so that the transmitter beam is directedinto the receptor uptake axis, i.e. with about 180 degrees angle betweenthe axis. This arrangement is advantageous when concentrating onradiation transmitted through the object, for example when absorption isa main parameter to be detected. The receptor can be placed anywherebetween the abovesaid extremes, to form any acute or obtuse anglebetween 0 and 180 degrees, such as about 90 degrees, to the transmitteraxis. This arrangement may be advantageous when concentrating ondetection of scattered radiation from the object, for example to detectimpurities or unclarity. It is possible to arrange several activeelements around the circle defined by rotating the receiver axis 0 to360 degrees in relation to the transmitter axis in the above exemplifiedway. For example, with one or more transmitters, it might be of interestto position one receiver at about zero degrees, one at about 180 degreesand one at about 90 degrees to obtain three signals maximizing responsesfor reflected, absorbed and scattered radiation respectively, which canbe of interest to obtain a more detailed object fingerprint or to makepossible corrections for the various response components in theradiation received, e.g. elimination of influence from scatteredradiation.

It has been assumed above that both the transmitter and the receiveraxes are in the same plane which is not necessary although generallyoptimal for strongest response. Space restrictions may require theplanes to be slightly displaced although still substantially parallel.The planes may also form and angle to each other, which may be useful toutilize available space or to obtain a semi-transmitted orsemi-reflected response from large object such as along a cartridgeaxis.

It is possible to make the active elements movable in relation to eachother and provide means to perform such movements, e.g. to obtain atomographic type scanning of the object, to allow a single activeelement to perform the action of several or to superpose a dynamiccomponent to a static measurement to facilitate or improve on signalprocessing. In most applications it is however sufficient and preferredto arrange the active elements mutually static for simplest design. Asindicated above it may also be of interest to allow for a relativemovement between the active components and the object, which can be doneby arranging the active elements movably in relation to the device butpreferably by making the object movable in relation to the device.Scanning speeds can be selected within broad limits and for example bedetermined with other than sensor considerations, such as the earliersuggested for cartridge movements. It is an advantage that low speedscan be used, even zero speed in case of stationary measurements.

Sensor Applications

As indicated the sensor system can be utilized to read informationgenerally in the form or a machine readable marking. The sensor systemmay also detect physical functional properties of the object observed. Amarking may also serve to facilitate detection of a functional propertysuch as a marking of a critical object position. For the purposes of thepresent invention the object “properties” for detection shall beunderstood to incorporate all these possibilities.

The nature of the information transferred by a machine readable markingsystem can be of any kind and is not limiting for the principles of theinvention. For the preferred medical delivery device application suchinformation may be of general nature such as security codes, patientcodes, administration schemes, calibration data etc. The data may be insome way related to the container such as container type or sizeidentification, stroke length or needle type for cartridges, contentpreparation type, volume and/or concentration, distribution data, batchnumber, storage capacity, temperature sensitivity, expire dates,classification according to official standards etc. The information maybe used for a variety of purposes such as simple display of theinformation to the user, setting of processor parameters, basis foracceptance or rejection of attached container, enabling or disablingdevice operation in response to patient data and security codes,selection or downloading of administration pattern, calculation of dosesetc.

In order to obtain the advantages stated in respect of marking readingit is preferred to use a non-imaging sensor system, as defined and mostpreferably a de-focused radiation method as defined. Preferably thereceptor has a divergent take-up angle for received radiation which mayhave a space angle of for example between 10 and 150 degrees, betterbetween 20 and 120 degrees and most preferably between 30 and 90degrees. The area covered on the marking by such a reception can stillbe controlled by the distance between the receptor and the marking. Inorder to concentrate the marking area the distance typically is lessthan 25 mm, preferably less than 15 and most preferably less than 10 mm.A certain area size is desirable to even out fluctuations and to permiteven irradiation and preferably said distance is above 0.1 mm,preferably above 1 mm and most preferably above 2 mm. The shape of thearea covered by the receptor may vary due to irradiation restrictions,geometry of receptor or its shielding and any curvature of the objectitself. Indicative of the absolute size of the area covered, expressedas the diameter of a circle with corresponding surface, may be between0.1 and 20 mm, preferably between 0.5 and 15 mm and most preferablybetween 1 and 10 mm in diameter.

The information is carried by detectable differences in any of thepossible optical properties discussed above. The area covered by thereceiver will generally give a unified and accordingly integratedresponse and it is hence possible that the abovesaid area size coveredby the receiver at any time is non-uniform, for example having agradient but preferably then a grid or raster pattern e.g. as used inprinting and graphics, although preferably the area covered issubstantially uniform to the radiation used. Even if possible that themarking covers only a part of the receiver covered area it is generallypreferred for strongest response that the entire area is marked.

Because of the analog response it is possible to have a multitude ofdetectable information levels from a single marking area. Theseinformation carrying levels may form a truly analog signal by beingdesigned to cover a continuum of possible levels, for example torepresent an equally truly analog characteristic such as containercontent volume or concentration, e.g. by being represented between fullreflection/transmission and full absorption. It is often preferred forsignal treatment reasons to design the marking system to give a multipleof discrete information level responses for simple afterprocessing, i.e.a digital system. Because of the many levels detectable such a digitalsystem shall preferably not be binary but based on more than twodifferent levels, preferably at least three and most preferably morethan three discrete levels, for example hundreds of levels. In order tofacilitate binary digital afterprocessing of the signal output, it maybe beneficial to adapt the multitude of possible levels to the binaryscale and to design the radiation detectable levels of the marking forexample to any 2^(n) value with n larger than 1 such as 4, 8, 16, 32,64, 128 or 256 discrete levels.

In spite of the amount of information possible to extract from a singlemarking area spot it may be desirable to include several suchinformation area spots in order to again and again multiply the possiblecombinations. Even if it is sufficient in a specific application withthe alternatives from one area it may be beneficial to include a controlarea, preferably with another level. Accordingly it is preferred to usemore than one area. In a truly analog system design such a multitude ofareas may form a continuous gradient. Preferably however the areas areseparated to give a step difference when read in sequence, possibly withstandard level surfaces separating each information carrying area tofacilitate discrimination between areas. The individual areas in such aset may be read by a number of individual receivers although preferredto use a single receiver, or a few for control, for scanning the set ofareas by relative movement according to any of the mechanisms earlierdescribed. Scanning may take place staticly or semi-staticly by movingthe receiver to an area and recording its level or preferably bycontinuously moving the receiver over the areas to get a dynamicallychanging response, or by a combination of these methods.

The marking can affect the radiation in any of the general mannersdescribed such as by differences in reflection or scattering butpreferably differences in absorption is employed. It is often sufficientto use differences in the total absorption over the bandwidth used,disregarding any frequency dependence, preferably by using absorbentsaffecting all frequencies in the bandwidth used about equal, whichallows for simplest signal processing and permit use of monochromeradiation. Alternatively or in addition absorbents altering thefrequency distribution can be used to create a correspondence to colorsin the visible range, which strongly increases the number ofcombinations. The frequency differences may by a receiver able to tunethe various bandwidth frequencies or preferably by using more than onereceiver sensitive in different bands. Differences in absorption can bedetected in transmitted radiation, by use of pigments or preferablydyes, but are preferably detected in reflected or scattered radiation,such as by placing transmitter and receiver close the same side of themarking. Although possible to arrange the marking over some other objectfeature to have a combined response therefrom it is generally preferredto isolate the marking response from other influences and for exampleuse an opaque or preferably reflecting backing behind the marking, suchas a metal sheet. As mentioned a suitable pigment system in visible andinfrared regions is carbon black and titanium oxide, having a fairlyuniform influence over a broad frequency range. The marking may bedirectly applied to the object for example by spraying or painting orthe marking may be indirectly applied by using a label or sticker,allowing common printing method to be used and facilitating applicationof backing materials.

In a medical delivery system the marking principle can for example beused to provide a set or system of at least two and preferably morecontainers, having different properties in at lest some respect, andproviding the containers with a machine readable marking of the naturedescribed which is designed to carry information allowing discriminationbetween the different container property types. The container may forexample be different in respect of preparation type, concentration,volume, size, cartridge diameter, security code, expire dates etc.Generally the marking would allow machine identification of containertype for any purpose, such as for rejecting containers with passedexpire dates, making the connection between a specific security code anda specific patient or machine screening, selection or sorting ofcontainers for any of its properties e.g. in manufacture, distributionor stock holding. Commonly the container will also be similar in somerespect, such as any of the above mentioned. Preferably the containersare similar in the respect that they are adapted for use in the samemedical delivery device, such as by having similar features forconnection to the attachment means, sizes adapted for use in the deviceand a geometry adapted for reading of its marking by the same sensorsystem. This will allow the device for example to reject containers notintended for use and to adapt to container types allowed.

Marked information may be brought to the device in any way, for examplevia a sensor arranged to receive such information specifically from aseparate information strip or via a marked dummy container. For highestsecurity it is preferred to bring the information to the device via amarking physically attached to the container, at least if theinformation in any way is related to the container as described.

As said the sensor system may also be used to detect a functionalproperty of the object. Contrary to the “marking” dealt with above, a“functional” property shall be understood as any characteristic of anobject not applied to transfer information to the device but is presentfor the intended operational purpose of the device or is the result ofthe object manufacturing or use history. In the preferred application ofmedical delivery devices sensing of a functional property normallyserves the purpose of determining or verifying adequate status of thecontainer to be used, e.g. to allow the control system to accept orreject the container or to adapt to its specific conditions or status orto monitor a process taking place therein. The functional property isgenerally a physical property of the container or its content and assuch difficult to falsify. Yet for safety reasons it is important thatthe detection is fail-safe.

In order to establish whether or not the functional property is presentat a container type object the container position is irradiated and theaffected radiation is received and compared with a predeterminedrepresentation of the characteristic to be detected. Normally thecontainer is in the container position but it might also be absent, forexample when the system searches for a non-present cartridge, when acalibration signal for the position as such is to be determined or whenmeasurement against a dummy is made. As a physical property is difficultto falsify any kind of radiation sensor system principle can beutilized. An imaging system, also in the visible range, can be utilized,for example to detect a contour part of the cartridge or a discontinuityin the container or content signaling a defect or impurity when comparedwith a representation of the proper condition. It is often preferredhowever to utilize a non-imaging system or most preferably such a systembased on de-focused radiation in order to exploit the general advantagesinherent therein as described, e.g. to obtain unique fingerprint ofseveral radiation type contributions or to combine in a simple system ofhigh security able to sense both marked information and functionalproperties. Although functional properties are often detected by aresponse dependent on radiation received from different depths, it ispreferred to receive radiation from about the same response angles andareas as stated for general or marked information use, if given as thearea of container part closest to the active elements.

It may also be beneficial to combine functional property sensing with arelative movement between receiver and container, for example to get thedynamic response signal earlier described, to sense in sequence bothmarked information and functional properties or to detect severaldifferent functional properties, or the variation of a single property,along a container, for example along the axial extension of a cartridgetype container. Movement of the container may also be part of a dynamicprocess to be monitored by the sensor system such as an emptying,filling, dilution or dissolution process or any of the abovedescribedinitiation steps for a cartridge type container. Any dynamic process canbe followed either staticly with container and receiver mutually fixedor dynamically with a relative motion therebetween. Below some examplesof various sensing options.

A contour part of the container may be sensed to verify if a containerhas been inserted in the device, that it has the intended size and thatit is properly positioned for example in relation to the attachmentmeans or its preset position if movably arranged. A highly specificcontour part, such as a flange or closure part may be selected if animaging sensor system is utilized. A non-imaging system can be used todetect the relative position of the contour, which response can behighly sensitive to even small positional differences if the receptionangle is small compared to the displacement to be detected and if thecontour is normally located within the angle area. If several orthogonalcontour lines are detected the entire container position will be welldetermined.

Internal features may be detected provided the container is transparentto the radiation. In particular it may be beneficial to detect a movablewall, especially a plunger in a cartridge type container, for example inorder to verify a fresh container by confirming that the piston is inits start position, verify completed initiation such as reconstitutionor deaeration by confirming the required displacement of the plunger orcontact between plungers in multichamber systems, determining doses leftin the container from a sensing of current plunger position or emptiedcontainer by verified end position. Preferably sensing can take place bythe absorption of the plunger material itself, optionally modified e.g.with an added absorbent, and preferably in reflected radiation. Theuptake area should be adapted to the plunger size, preferably so that itcovers only a part of its axial extension making it possible to detectdetails thereof, such as sealing rings, even in non-imaging orde-focused radiation. With preference a cartridge for this purpose canhave a plunger position exposed for sensing and a marking carryinginformation at another part, which marking is readable in non-imagingradiation and accordingly allows sensing for both purposes by the samesystem.

Also the internal container content can be sensed. Presence of a solidcan be detected by its absorption or scatter and the presence of aliquid can be distinguished from a gas by the difference in refractiveindex, for example in transmitted radiation at an off-center line wherethe difference in refraction give a detectable response difference. Alsoimpurities in an otherwise homogeneous media, e.g. liquid or gas can bedetected, such as unclarities or miscolorations or gas or particleinclusions by increased scatter or total absorption change form a smalluptake area. Similar methods can be used to detect deficiencies in thecontainer walls such as cracks or deformations. Preparation type can bechemically verified by measurement at spectral wavelengths typical forthe product. Marking or modifications may be used to facilitate oramplify the response at detection of functional properties. For example,instead of determining a container position on the basis of a physicalstructure thereof a marking or at least one or preferably several spotson the container of label may serve the purpose of defining thecontainer orientation. Verification of container presence can similarlybe done by the detection of a predetermined marking. A modification mayalso take the form of an attached mirror reflecting part on thecontainer or a prism reflecting or refracting facet thereon, preferablyarranged to divert transmitter radiation towards the receiver.

Although the invention has been described in relation to deliverydevices it is clear that the system principles can be used for anysimilar or entirely different purpose. For example, the marking systemhas a general utility and is not restricted to marking of containers butmay be used on any article or for any information transfer purpose. Thesensor for reading such a marking must not be included in a deliverydevice but can be included in any other device or in a general purposereader. Similarly the general principle of detecting a functionalproperty by its radiation fingerprint need not be restricted toproperties of containers but can have a general utility for otherarticles, e.g. to detect their presence, position, appearance structureat the surface or at depth similar to any of the abovedescribedapplications, and the sensor be included in any identification system.Accordingly the system may be used as a general device or method foranalysis of an object, e.g. for color analysis at any frequency range orfor surface or depth structure or texture analysis of any object.

Signal Processing

Processing of the signal received from the receiver can take place inany processor located anywhere, for example to continuously orintermittently by intermediate storage transmit the signal to a remotecomputer for processing in real or artificial time. Preferably thesignal is fed to an on-board microcontroller of the device and in mostinstances it is also preferred to process the signal in real time. Theprocessing will be described in terms of these options.

The signal processing for the sensor system will be different dependingon which system principle is utilized. A system based on an imagingsensor system may need a signal processing able to make a connectionbetween receiver individual pixel responses in space or time to aspecific point in space, which may require parallel processing of allpixel responses, connection of each pixel response to an absolute gridaddress, syncronization of line sweeping to absolute start positionsetc. Signal analysis may then incorporate any known system for imageanalysis, e.g. by comparing the signal with a predeterminedrepresentation of the object property to be detected.

In the preferred embodiment of a non-imaging system signal processingcan basically be kept very simple. The transmitter can be made give offa stable radiation and the receiver to receive part thereof. The outputfrom the receiver may be a stable level response, such as a stablevoltage, for example when the object is non-changing or when there is norelative movement between receiver and object, whereby a substantially“static” response is relied upon. The predetermined representation ofthe property to be identified can then similarly be a level and theprocess of comparison may include any algorithm for comparing themeasured level with one or several predetermined levels to determinewhether or not the sought property shall be deemed present. Preferablythe response in measured several times or over a certain time to averageout any small disturbances or variations.

A more reliable measurement can be obtained when detecting and comparingmore than one part of the object, preferably parts with differences inresponse levels. Hereby “relative” rather than “absolute” levels can bedetermined by comparison which among others improve reliability.Relative measurements can be made in a “semi-static” method by makingmore than one static measurement on different object parts. At sensingof marked parts several markings, including separate reference levels orconstituting mutual reference levels, can be read and used to establishresponse level differences. Similarly when sensing a functional propertymore than one measurement can be done at the site of interest and atanother site, e.g. at plunger position and a plunger absent position orat filled and empty container parts, or at two points of differentresponses at the same object, e.g. at plunger sealing rings andtherebetween respectively. Alternatively or in addition a relativemeasurement can be based on differences in radiation responses atdifferent wavelengths, if present, at the same object area. The signalprocessing may here incorporate an establishment of the responsedifference or ratio between the sensed parts and comparison of thisrelative level between one or several predetermined level differences orratios.

It is generally preferred to include a “dynamic” action to the signal,i.e. to provoke a signal changing over time and in some way record andact on the response versus time function. A dynamic response may serveto provide a relative response in the same way as the semi-static methodalthough with more data available for elimination of random factors. Adynamic method also generally permits extraction of more information forcalculation and decision making owing to the time axis present, such asrate of change or floating average or noise level calculations. Signalprocessing may here include comparison with a sequence of relativelevels to be confirmed, possibly independent of time, or a more completecurve fit for more elaborate analysis. A dynamic response can be causedin several ways. A continuous change in sensor system frequency maycause a varying response. A monitoring of a dynamic process, such as thedissolution of a compound or the movement of a piston, can be followedover time. As indicated a preferred dynamic response is caused by arelative movement between object and sensor, which may serve both toread a sequence of markings and several different object functionalparts along the movement track or several details along the same objectpart giving a more detailed fingerprint thereof.

The above described dynamic method, wherein receiver output is monitoredfor its amplitude versus time function, directly or indirectly, and thefunction processed before an activity is based thereon, is highlycompatible with existing processor technology. The function may beobtained and treated as continuous but it is preferred that values aresampled from the device output, which may be made at irregular butpreferably at regular time intervals at a certain frequency. Samplingcan be in any of several known ways. The sampling may be digital in thesense that the amplitude is compared with a reference level and eitherset to a binary 1 or a binary 0 depending on whether the amplitude isabove or below the reference level, which may be varying but preferablyis fixed. Among others for extracting more information from the raw dataan analog sampling method is generally preferred, in which the functionabsolute amplitude value is repeatedly registered. The analog value canbe processed in an analog processor but it is mostly preferred toconvert the value to digital form and process it in a digital processor.The signal may in a manner known per se be filtered to remove certainfrequency ranges.

The signal processing may include a function comparable with automaticgain control, either by hardware or by software, meaning that systemamplification at the response level of interest is adapted to thepresent purpose of either overview or magnification.

The function values may be memorized and processed at any time and ratebut real time processing is generally preferred in most applications,which may still require some memorizing of the values to besimultaneously processed at any given time. It is preferred that theprocessing involves at least two, preferably three and most preferably amultiple of function values at a time.

In all of the above discussed signal processing methods it is possibleto use several transmitters and receivers at a time. This may be donefor any of the reasons earlier discussed, such as collection ofradiation from different angles to allow calculation of a correctedresponse. Specifically for the now discussed objects it may be ofinterest in the static method to use several receivers to sensedifferent object parts, in the relative measurement method additionallyto simultaneously sense the levels on which the relative measurementsare based or to collect responses at several frequencies and in thedynamic method additionally to cover several aspects of the processmonitored.

In any of the methods discussed it is also preferred to modulate thetransmitter signal and to detect the modulation at the receiver outputsignal. This in order to exclude influence from random factors anddisturbances not having the modulated characteristic. A highly advancedmodulation can be used although it is often sufficient to superimpose onthe radiation a stable modulation frequency. Such a frequency should beclearly above the ubiquitous power line frequencies with overtones andcan for example be above 0.5 kHz and preferably above 1 kHz but can bekept below 1000 kHz and preferably below 100 kHz. The receiver systemshould be tuned to the modulation frequency as narrow as possible, butcan have a small bandwidth in case doppler shifts are to be detected.Filtering of the signal can be made with any known method based onhardware or software.

The above exemplified signal processing steps shall not exclude anyother type of common processing. In particular any processing mayrequire normal initializing steps, such as zeroing or the system bymeasurement of the background radiation immediately before insertion ofa container or normalization against a standard dummy container orreference marking absorbency level.

SUMMARY OF DRAWINGS

FIG. 1 a and 1 b show schematically active elements arranged at acartridge type container.

FIG. 2 is a diagram of an actual response in reflected radiation from ascanning over a plunger position.

FIG. 3 is a simplified flow block diagram over suitable electronics fora sensor system according to the invention.

FIG. 4 is a detailed circuit diagram for use in the electronics of FIG.3.

FIG. 5 is examples of labels with markings to be read by the sensor.

FIG. 6 a to 6 d show schematically a pump device and a dual chambercartridge in four stages of operation.

DESCRIPTION OF DRAWINGS

FIG. 1 a and 1 b show in schematic form a cartridge type containergenerally designated 1 and having a cylindrical part 2 and containing aplunger 3 having three sealing rings 4. Attached to the cylindrical part2 is a label 5 assumed to bear coded surfaces on a totally reflectivebacking. A transmitter is indicated at 6, giving off radiation in theform of a wide cone 7. A first receiver 8 is arranged close totransmitter 6 and facing in the same direction and which receivercollects radiation from a cone 9 which is somewhat more narrow thantransmitter cone 7. A second receiver 10 is arranged, relative thetransmitter 6, on the opposite side of the container and facing towardsthe transmitter 6. A third receiver 11 is arranged at about right anglerelative the transmitter 6 axis and facing towards container interior.In the relative positions shown the transmitter 6 radiation is directedtowards the label 5 and the first receiver 8 collects radiationreflected from the label part irradiated by the transmitter 6. As thelabel is not translucent receivers 10 and 11 do not receive any directradiation from the transmitter 6 but may receive random radiationscattered in a housing or entered from the surroundings and theiroutputs may be used to correct the response from the first receiver 8for any such background radiation. If the container is axially displacedso that the plane of active elements becomes positioned at 12, that isbetween label 5 and plunger 3, the response from the receivers will beentirely different. Assuming that the container 1 is transparent someradiation will be reflected at the outer and inner surfaces of theradiation entering side of the container, similar reflections will occurat the radiation exit side of the container, absorbtion will take placein the walls and possible container content and some scattering willtake place at all these events. The change in output from the receiverscan easily be detected, i.e. the second receiver 10 may receiveconsiderably more radiation than when behind the label. If the containeris further displaced to locate the plane of active elements at theplunger 3 the receiver signals will again change and in particular thefirst receiver 8 will record the typical radiation reflected from theplunger, which sensing can be static or dynamic if made during movementof the container and in the latter case the difference in response atand between the sealing rings 4 may be detected.

FIG. 2 shows an actual response from a sensor system operating in theinfrared region when passing over a plunger with three sealing ringsinserted in a transparent syringe type container. The vertical axisgives the response level from the receiver in digitized values between 0and 256 and the horizontal axis lengths in arbitrary units. The threecurves represent the response when measured through transparentfiltering labels being, from above, clear, green and blue respectively.It can be seen that the differences in response at the three sealingrings of the plunger are clearly detectable, even when the filteringlabel has a color closely resembling the color of the plunger material,as in the lowermost curve.

FIG. 3 is a block diagram over the main functions in a suitable sensorsystem according to the invention. A microcontroller 31 activates anddeactivates the transmitter 34 over a modulator 32 and amplifier 33 togive a 3 kHz varying output from the transmitter having a nominalwavelength of 940 nm. The radiation hits and is affected by an objectsurface 35 and part of the radiation is collected by the receiver 36.The output signal from the receiver 36 is filtered in a bandpass filterto extract frequency components narrowly around the 3 kHz modulationfrequency. This signal is amplified in 38 and fed to an A/D converter 39and the digital output is returned to the microcontroller 31. Based onthe signal received and on comparison levels of interest themicrocontroller 31 may activate an automatic gain control unit (AGC) 40to deliver a reference level to the A/D converter to permit a shift ofreference level and level range resolution for the digitalization. Themicrocontroller may have access to software for bandpass filtering, theAGC function and for example cluster analysis for comparison of receiverresponse with predetermined characteristics to be identified.

The circuit of FIG. 4 is basically composed of three parts, a powersupply part shown at the lower section of the drawing, an analogradiation part shown in the middle section and a digital processing partshown at the top. The radiation signal for the LED transmitter ismodulated from the processor U4 (pin 28, “s”) via the transistor Q1 ofthe transmitter diode D5 (TSMS3700). The radiation from the objectimpinges on the photo diode receiver D4 (BP104FS) and is transformedinto a current. The radiation part further comprises double filteringand amplifier steps where the filters are of bandpass type, i.e. eachfilter includes both a low pass and a high pass filter. The signalenters the high pass filter C8, R23, R24, is amplified in U2A and entersthe low pass filter C10, R25, R26. The procedure is repeated in highpass filter C9, R22, amplifier U2B and low pass filter C11, R27, R28.After these analog steps the signal enters the A/D converter, being partof the microcontroller U4. The signal is processed in digital form inthe microcontroller U4 by use of software, e.g. digital filtering,sorting and comparing algorithms etc. The resistors R4 to R11 acttogether with the microcontroller as an AGC function, allowing detailedanalysis of different amplitude levels.

FIG. 5 shows a simple label with markings to be used on a cartridge typeof container for example as illustrated in FIG. 6. The label 50 has afirst large uniformly colored area 51 with predetermined absorption,which is intended to be read staticly, i.e. when the area is kept fixedin relation to the sensor. The absorption level of the surface may bringinformation about the cartridge type, content or concentration or may beused for calibration purposes. Field 52 is a window in the label whichwindow is entirely clear and transparent and which window is intended toallow sensing of cartridge interior and especially the presence of aplunger. Fields 53, 54 and 55 are again uniformly colored areas ofpreferably different absorption levels which carry information of forexample the same type as area 51. The window 52 and the fields 53, 54and 55 are intended to be read dynamically in sequence under relativemovement between label and sensor as indicated by arrow 56. A sensor isindicated in phantom lines at 57 in a first position over the staticfield 51. After reading of this field the cartridge with the label ismoved in direction of arrow 56 which will cause window 52 and fields 53,54 and 55 to pass across the sensor 57 to produce a response versus timefunction processable by electronics. It is assumed that all labelsurface except the window 52 is substantially non-transparent, bysufficient pigmentation or an opaque backing, to be unaffected byradiation from behind the label.

FIG. 6 a to 6 d show schematically four operational stages of a pumppart 60 and a dual-chamber type cartridge 70. The pump 60 comprises ahousing 61, a piston rod type member 62 and an electromechanical unitgenerally designated 63 operable to actuate and control the rod to bothmove the cartridge 70 and expel its content. With preference these pumpparts are constructed according to the above referenced co-pendingapplication. A sensor 64 is arranged at the intended cartridge positionof the pump 60. The cartridge comprises a barrel 71, an outlet 72, arear plunger 73 and a front plunger 74. On the barrel outside isattached a label for example as described in FIG. 5.

FIG. 6 a shows the relative positions of pump 60 and cartridge 70 whenthe cartridge has just been attached to the pump with the piston rod 62close to the rear plunger 73. The sensor 64 is located at the rearplunger 73 and over a first part of the label 75, for example the staticfield 51 of FIG. 5, which label part is read by the sensor 64.

FIG. 6 b shows a position in which the unit 63 has caused the cartridge70 to move towards the pump part 60 while concurrently abutting the rearplunger 73 to maintain its absolute position. Accordingly rear plunger73 is still at the sensor 64 but the label 75 is supposed to havetraveled to a position where window 52 is between sensor 64 and plunger73. The sensor can now verify proper plunger 73 position andcharacteristics through label window 52.

FIG. 6 c shows a position when unit 62 has caused the cartridge to movestill further towards the pump under movement of the plunger 73 to aposition within barrel 71 where it is in contact with the front plunger74, and perhaps the two plungers have moved a certain distance together,and the cartridge is in its final position relative the pump unit 60.Under this cartridge movement the remaining parts of label 75 havepassed the sensor 64 to enable a dynamic reading of fields 53, 54 and 55and extraction of any information encoded therein.

FIG. 6 d shows a position wherein unit 63 has caused member 62 to moveforward to expel the cartridge content in front of plunger 74 throughoutlet 72. Under this operation sensor 64 may monitor the disappearanceof plunger 73, proper clearance of barrel 71 and detection of a markingon member 62 signaling arrival at its forward extreme position.

The exemplified embodiments are illustrative only and shall not beunderstood in any way limit the scope or generality of the invention asdefined in the claims.

1. A preparation delivery device comprising a) a container for thepreparation having or being prepared for the arrangement of an opening,b) a mechanism operable to deliver at least part of the preparation inthe container through the opening, c) attachment means for connection ofthe container to the mechanism and d) a sensor system arranged to detectat least one predetermined property of the container or its content,characterized in the improvement comprising a radiation transmitterarranged to irradiate the container position or a part thereof, aradiation receiver arranged to receive at least an area part of theradiation from the transmitter after the radiation having been affectedby the container position and the receiver being designed to give anoutput response representative for the total radiation received fromsaid area part.
 2. The device of claim 1, characterized in that at leastpart of the container is translucent or transparent at the radiationfrequency.
 3. The device of claim 1, characterized in that the containeris a cartridge comprising a) a generally cylindrical barrel with ageneral symmetry axis and having a front end and a rear end, b) anopening or a preparation for an opening at its front end, c) at leastone displaceable piston inserted in the barrel between the front end andthe rear end.
 4. The device of claim 3, characterized in that thecartridge is of dual or multi chamber type.
 5. The device of claim 1,characterized in that the mechanism includes pump means actuated byelectric motor means.
 6. The device of claim 1, characterized in thatthe mechanism includes a control system operable to control at least theelectric motor means.
 7. The device of claim 1, characterized in thatthe attachment means include movement means operable to move thecontainer in relation to stationary parts of the mechanism.
 8. Thedevice of claim 7, characterized in that the movement means includescanning means operable to move the container relative the sensorsystem.
 9. The device of claim 8, characterized in that the movementmeans are also operable to perform an initiation operation on thecontainer.
 10. The device of claim 7, characterized in that saidmovement means are arranged to give a speed of less than 10 cm/sec,preferably less than 1 cm/sec.
 11. The device of claim 1, characterizedin that the radiation has a wavelength between 300 and 3000 nanometers.12. The device of claim 11, characterized in that the radiation is inthe non-visible range.
 13. The device of claim 12, characterized in thatthe radiation is in the infrared range.
 14. The device of claim 1,characterized in that the transmitter comprises a light emitting diode.15. The device of claim 1, characterized in that the receiver comprisesa photodiode or a phototransistor.
 16. The device of claim 15,characterized in that the receiver comprises a daylight filter.
 17. Thedevice of claim 1, characterized in that the receiver output isnon-imaging.
 18. The device of claim 1, characterized in that theradiation received is de-focused.
 19. The device of claim 1,characterized in that the irradiation and reception have space anglesabove 10 degrees.
 20. The device of claim 1, characterized in that thetransmitter is arranged to give a divergent beam and the receiver isarranged to have a divergent take up angle.
 21. The device of claim 1,characterized in that transmitter and/or receiver are broadbanded with apreferred frequency variation coefficient of at least plus and minus 1percent of nominal frequency.
 22. The device of claim 1, characterizedin that transmitter and receiver are arranged facing in substantiallythe same direction.
 23. The device of claim 1, characterized in that thetransmitter and receiver are arranged at a distance from the container.24. The device of claim 1, characterized in that the area covered by thereceiver, expressed as the diameter of a circle with correspondingsurface, is between 0.5 and 15 mm.
 25. The device of claim 1,characterized in that the container has a marking readable by the sensorsystem.
 26. The device of claim 25, characterized in that the markinghas more than two discrete levels.
 27. The device of claim 25,characterized in that the marking has several discrete marking areas.28. The device of claim 27, characterized in that moving means arepresent to read the areas in sequence, staticly or dynamically.
 29. Thedevice of claim 25, characterized in that the marking has differences inabsorption or reflection.
 30. The device of claim 1, characterized inthat the relative positioning between sensor and container is adapted todetect a functional property of the container.
 31. The device of claim30, characterized in that the functional property is a container contourpart a plunger position, container content or a marking or modificationdesigned to facilitate detection of a functional property.
 32. Thedevice of claim 30, characterized in that the relative positioning isadapted to also read a marking on the container, staticly ordynamically.
 33. The device of claim 1, characterized in that itcontains an electronic control unit, preferably a microcontroller. 34.The device of claim 33, characterized in that the control unit isoperative to receive the modified or unmodified output from the receiverand compare it with one or several memorized characteristics and to actdifferently if and if not, respectively, a certain similarity ispresent.
 35. The device of claim 34, characterized in that the controlunit is operative to receive a response versus time function.
 36. Thedevice of claim 34 or 35, characterized in that said acting includes theoption of activating electric motor means.
 37. The device of claim 1,characterized in that the transmitted radiation is modulated.
 38. Thedevice of claim 1, characterized in that transmitter and receiver arearranged to have a stable axis orientation in relation to their support.39. The device of claim 38, characterized in a fixed arrangement of thesupport in relation to the mechanism or a housing.
 40. A method foroperating a preparation delivery device comprising a) a container forthe preparation having, or being prepared for the arrangement of, anopening, b) a mechanism operable to deliver at least part of thepreparation in the container through the opening, c) attachment meansfor connection of the container to the mechanism and d) a sensor systemarranged to detect at least one predetermined property of the containeror its content, characterized in the improvement comprising transmittingradiation towards the container position or a part thereof to allow theradiation to be affected by the container position, receiving at least apart of the affected radiation from at least an area part of thecontainer position in a non-imaging way and comparing thecharacteristics of the received radiation with a predeterminedcharacteristic representative for the predetermined property toestablish whether or not the predetermined property of the container ispresent.
 41. The method of claim 40, characterized in that the radiationis affected by reflection, transmission, absorption and/or scattering.42. The method of claim 40 or 41, characterized in that at least part ofthe container is translucent or transparent at the radiation frequencyand that at least some radiation is transmitted into the container. 43.The method of claim 40, characterized in the step of moving thecontainer in relation to stationary parts of the mechanism.
 44. Themethod of claim 40 or 43, characterized in the step of performing aninitiation step on the container.
 45. The method of claim 44,characterized in that the initiation step comprises a reconstitutionstep.
 46. The method of claim 40 or 43, characterized in the step ofmoving the container in relation to the sensor system.
 47. The method ofclaim 46, characterized in that the speed of movement is less than 10cm/sec.
 48. The method of claim 40, characterized in that the speed isless than 1 cm/sec.
 49. The method of claim 40, characterized in thatcontainer and sensor system are kept stationary in relation to eachother during radiation reception.
 50. The method of claim 40,characterized in that the radiation transmitted is in the non-visiblerange, preferably in the infrared range.
 51. The method of claim 40,characterized in that the radiation received is de-focused.
 52. Themethod of claim 40, characterized in that the radiation is transmittedin a divergent beam and the radiation is received from a divergent takeup angle.
 53. The method of claim 40, characterized in that that theradiation is transmitted and received in a broad space angle, preferablyabove 30 degrees.
 54. The method of claim 40, characterized intransmitting and/or receiving a broadbanded radiation with a preferredfrequency variation coefficient of at least plus and minus 1 percent ofnominal frequency.
 55. The method of claim 40, characterized in thattransmitter and receiver are arranged facing in substantially the samedirection an that at least some radiation received is reflected.
 56. Themethod of claim 40, characterized in the step of maintaining transmitterand receiver at a distance from the container.
 57. The method of claim40, characterized in that the area covered by the receiver, expressed asthe diameter of a circle with corresponding surface, is between 0.5 and15 mm.
 58. The method of claim 40, characterized in the step ofproviding a marking on the container readable by the sensor system. 59.The method of claim 58, characterized in providing the marking with morethan two discrete levels.
 60. The method of claim 58, characterized inproviding more than one discrete marking areas.
 61. The method of claim60, characterized in reading the areas in sequence, staticly ordynamically.
 62. The method of claim 61, characterized in that thereading gives a step difference in the response.
 63. The method of claim58, characterized in providing a marking with differences in absorptionor reflection.
 64. The method of claim 40, characterized in positioningsensor and container to allow detection of a functional property of thecontainer.
 65. The method of claim 64, characterized in that thefunctional property is a container contour part, a plunger position,container content or a marking or modification designed to facilitatedetection of a functional property.
 66. The method of claim 64,characterized in also reading a marking on the container, staticly ordynamically.
 67. The method of claim 40, characterized in that in thecomparing step the characteristic of the received radiation is aresponse representative for the total radiation received from said areacovered.
 68. The method of claim 67, characterized in that saidestablishment of property presence is based on a static response fromthe receiver.
 69. The method of claim 67, characterized in that saidestablishment of property presence is based on a dynamic change from thereceiver.
 70. The method of claim 69, characterized in that theestablishment involves recording a dynamic response versus time functionfrom the receiver.
 71. The method of claim 70, characterized in thatmore than one property presence is established.
 72. The method of claim71, characterized in that at least one marking property and onefunctional property is established.
 73. The method of claim 40,characterized in that the transmitted radiation is modulated.
 74. Themethod of claim 40, characterized in that the radiation is transmittedand received with stable orientation in relation to stationary parts ofthe mechanism.
 75. The method of any of claims 40 to 74, characterizedin that the container is a cartridge comprising a) a generallycylindrical barrel with a general symmetry axis and having a front endand a rear end, b) an opening or a preparation for an opening at itsfront end, c) at least one displaceable piston inserted in the barrelbetween the front end and the rear end.
 76. The method of claim 75,characterized in that the cartridge is of dual or multi chamber type.77. A method for operating a preparation delivery device comprising a) acontainer for the preparation having, or being prepared for thearrangement of, an opening, b) a mechanism operable to deliver at leastpart of the preparation in the container through the opening, c)attachment means for connection of the container to the mechanism and d)a sensor system arranged to detect at least one predetermined propertyof the container or its content, characterized in the improvementcomprising transmitting radiation towards the container position or apart thereof to allow the radiation to be affected by the containerposition, receiving at least a part of the affected radiation andcomparing the characteristics of the received radiation with apredetermined characteristic representative for the predeterminedproperty, being a functional property as defined, to establish whetheror not the predetermined functional property of the container ispresent.
 78. The method of claim 77, characterized in that the receivedradiation is used to reproduce details from the container position in atleast two dimensions providing a representation in the form of pixels inthe at least two dimensions.
 79. The method of claim 78, characterizedin refracting the received radiation to an image on a cathode ray tubeor charge coupled device.
 80. The method of claim 78, characterized insweeping the container position point by point to produce an image. 81.The method of claim 77, characterized in transmitting and/or receiving abroadbanded radiation with a preferred frequency variation coefficientof at least plus and minus 1 percent of nominal frequency.
 82. Themethod of claim 81, characterized in transmitting at least part of theradiation to the content of the container.
 83. The method of claim 81,characterized in receiving at least part of the radiation as reflectedin substantially the opposite direction as transmission.
 84. The methodof claim 77, characterized in that the functional property is acontainer contour or a plunger position.
 85. The method of claim 77,characterized in any of the characteristics of claims 41 to
 76. 86. Asystem of marked medical containers comprising a) at least twocontainers having different properties in at least one respect and b) atleast one machine readable marking difference on each of saidcontainers, the marking being designed to allow discrimination betweensaid differences in properties, characterized in the improvementcomprising that the marking provides said difference by having at leastone area with different absorbance or reflectance when irradiated withradiation in non-visible frequency ranges.
 87. The system of claim 86,characterized in that the marking has more than two discrete levels. 88.The system of claim 86, characterized in that the marking has severaldiscrete marking areas.
 89. The system of claim 87, characterized inthat the areas provide step level changes whenread in sequence, staticlyor dynamically.
 90. The system of claim 86, characterized in that themarking has differences in absorbtion or reflection.
 91. The system ofclaim 86, characterized in that the markings provide an alteration inradiation frequency distribution.
 92. The system of claim 86,characterized in that the marking has an opaque or reflecting backing.93. The system of claim 86, characterized in that the areas have a size,expressed as the diameter od a circle with corresponding surface, of atleast 1 mm, preferably at least 2 mm and most preferably at least 5 mm.94. The system of claim 86, characterized in that the containers havesimilar functional properties in at least one respect.
 95. The system ofclaim 94, characterized in that the containers are similar in therespect that they are adapted to be used in the same medical deliverydevice.
 96. The system of claim 94, characterized in that the containersare similar in that they contain at least one common medical compound.97 The system of claim 86, characterized in that the difference inproperty comprises a difference in content medical compounds, contentvolume or content concentration.
 98. A syringe cartridge type container,for use with a preparation delivery device, comprising a) a generallycylindrical barrel with a general symmetry axis and having a front endand a rear end, b) an opening or a preparation for an opening at itsfront end, c) at least one displaceable piston inserted in the barrelbetween the front end and the rear end and d) a machine readable markingon the container, characterized in the improvement comprising that themarking includes at least one marking area with detectable absorbency orreflectance when irradiated with radiation in non-visible frequencyranges, that the piston has at least one surface part with detectableabsorbency or reflectance when irradiated with radiation in non-visiblefrequency ranges and that said piston surface part is exposed orexposable to the radiation through at least a part of the barrel andthat at least a part of said marking area and said piston surface partare located at the same position along the barrel symmetry axis.
 99. Thecartridge of claim 98, characterized in that at least a part along thebarrel axis is free from marking allowing exopsure of the piston. 100.The cartridge of claim 98, characterized in that in addition to themarking area covering the piston position at least one further markingarea with different absorbency or reflectance is arranged along thebarrel axis.
 101. The cartridge of claim 98, characterized in that thecartridge is of dual or multi chamber type having more than one piston.102. A machine readable marking system comprising at least two discreteareas of different detectable absorbencies when irradiated individuallyand providing a number of information carrying combination possibilitieswhen read in predetermined sequence, characterized in the improvementcomprising that each area comprises more than two discrete levels ofabsorbencies.
 103. The system of claim 102, characterized in that themarking has several discrete marking areas.
 104. The device of claim103, characterized in that the moving means are present to read theareas in sequence, staticly or dynamicly.
 105. The device of claim 102,characterized in that the marking has differences in absorbtion orreflection.
 106. A device for analysis of an object comprising a) aradiation transmitter arranged to irradiate and be affected by theobject and b) a receiver arranged to receive at least a part of thetransmitted and affected radiation and to deliver a signalcharacteristic for the received radiation, characterized in theimprovement comprising that the transmitter is arranged to irradiate theobject with non-imaging radiation, that the receiver is arranged tocollect non-imaging radiation affected by an area part of the object andthe receiver being designed to give an output response representativefor the total radiationi received from said area pert.
 107. The deviceof claim 106, characterized in any characteristic of claims 2 to 39.